Bio Balls

[Beardie 0]

In relation to a sump with bio balls and a spinning arm, is it best to keep the actual water level in the sump as low as possile so that more bio balls are not submerged. I heard that they work best when water just drips down from them, rather than being submerged. Any imput on that?

[Adam 0]

Indeed trickle filters are slightly more effective than submerged filters. the film of water can theoretically provide better gas exchange (CO2, O2, etc). So if there were no other practical reasons we would all have trickle filters.

I have submerged filters because if I used trickle filters with the regular power outs that I get, my filter would not work as effectively. Prolonged power outs would mean media dries out and I lose a larger percentage of my bacteria in a trickle compared to a submerged. There are a lot more reasons for using one or another. Its really personal preference.

I also think that the small amounts of media that we use in "typical" aquariums it does not really make much difference. The depth of your sump should be high enough to cope with evaporation from your tank between water changes. There also needs to be enough "free board" to cope with the standing water when your pump is switched off. There probably more important considerations than whether you have trickle or submerged. If you really want to get into the highly efficient filters that cope the best with changing bioloads you would use a Fluidised Bed Filter.

Hope that helps.

Adam